An accepted method of protection for industrial sensors such as fire and gas detectors in North America is the explosion proof method, known as XP, which ensures that any explosive condition is contained within the sensor enclosure, and does not ignite the surrounding environment. In Europe, the term “flame proof,” known as Ex d, is used for an equivalent method and level of protection: in this description, the terms “explosion proof” and “flame proof” are used synonymously to avoid global variations in terminology. Explosion proof sensors have utility in many applications, including those involving toxic or flammable gases or liquids, and high pressure gas systems. There are established standards for explosion proof or flame proof systems, and systems can be certified to meet these standards. Some of the standards that are widely accepted by the industry and government regulatory bodies for explosion-proof or flame-proof design are CSA C22.2 No. 30-M1986 from the Canadian Standards Association, FM 3600 and 3615 from Factory Mutual, and IEC 60079-0 and 60079-1 from the International Electrotechnical Commission.